Provided by: grass-doc_7.6.1-3_all bug

NAME

       v.select  - Selects features from vector map (A) by features from other vector map (B).

KEYWORDS

       vector, geometry, spatial query

SYNOPSIS

       v.select
       v.select --help
       v.select  [-tcr]  ainput=name   [alayer=string]   [atype=string[,string,...]]  binput=name
       [blayer=string]        [btype=string[,string,...]]       output=name       operator=string
       [relate=string]   [--overwrite]  [--help]  [--verbose]  [--quiet]  [--ui]

   Flags:
       -t
           Do not create attribute table

       -c
           Do not skip features without category

       -r
           Reverse selection

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       ainput=name [required]
           Name of input vector map
           Input vector map from which to select features (A)

       alayer=string
           Layer number (vector map A)
           Vector  features  can have category values in different layers. This number determines
           which layer to use. When used with direct OGR access this is the layer name.
           Default: 1

       atype=string[,string,...]
           Feature type (vector map A)
           Input feature type
           Options: point, line, boundary, centroid, area
           Default: point,line,area

       binput=name [required]
           Name of input vector map
           Query vector map (B)

       blayer=string
           Layer number (vector map B)
           Vector features can have category values in different layers. This  number  determines
           which layer to use. When used with direct OGR access this is the layer name.
           Default: 1

       btype=string[,string,...]
           Feature type (vector map B)
           Input feature type
           Options: point, line, boundary, centroid, area
           Default: point,line,area

       output=name [required]
           Name for output vector map

       operator=string [required]
           Operator defines required relation between features
           A  feature is written to output if the result of operation ’ainput operator binput’ is
           true. An input feature is considered to  be  true,  if  category  of  given  layer  is
           defined.
           Options:  overlap,  equals,  disjoint, intersects, touches, crosses, within, contains,
           overlaps, relate
           Default: overlap
           overlap: features partially or completely overlap
           equals: features are spatially equals (using GEOS)
           disjoint: features do not spatially intersect (using GEOS)
           intersects: features spatially intersect (using GEOS)
           touches: features spatially touches (using GEOS)
           crosses: features spatially crosses (using GEOS)
           within: feature A is completely inside feature B (using GEOS)
           contains: feature B is completely inside feature A (using GEOS)
           overlaps: features spatially overlap (using GEOS)
           relate: feature A is spatially related to feature B  (using  GEOS,  requires  ’relate’
           option)

       relate=string
           Intersection Matrix Pattern used for ’relate’ operator

DESCRIPTION

       v.select  allows  the  user  to select features from a vector map by features from another
       one.

       Supported operators (without GEOS; using GRASS’ own algorithm):

           ·   overlap - features partially or completely overlap (GEOS equivalent: intersects)
       Supported operators (internally using GEOS - Geometry Engine, Open Source):

           ·   equals - features are spatially equals

           ·   disjoint - features do not spatially intersect

           ·   intersects - features spatially intersect (equivalent to native ’overlap’)

           ·   touches - features spatially touches

           ·   crosses - features spatially crosses

           ·   within - feature A is completely inside feature B

           ·   contains - feature B is completely inside feature A

           ·   overlaps - features spatially overlap

           ·   relate - feature A is spatially related to feature B

NOTES

       Only features with category numbers will be considered. If required the v.category  module
       can  be  used to add them. Typically boundaries do not need to be given a category number,
       as an area’s attributes are inherited from the  centroid.  Typically  points,  lines,  and
       centroids  will  always  want  to  have a cat number. E.g. take a road which separates two
       farms. It is ambiguous as to which farm an attribute that is attached to the road  belongs
       to.  The boundary only needs a cat number if it will hold its own attributes, such as road
       name or pavement form. A centroid in each paddock holds the information  with  respect  to
       ownership, area, etc.

EXAMPLES

       Preparation of example data (North Carolina sample dataset):
       # Create an grid for overlaying to ZIP code vector map
       v.mkgrid map=boxgrid grid=10,10 position=coor \
                coordinates=583600,201500 box=5000,5000
       # set region to ZIP codes and boxgrid vector maps
       g.region vector=zipcodes_wake,boxgrid -p res=100 -a
       # enlarge region a bit for "white border" around map in monitor
       g.region n=n+1000 s=s-1000 w=w-1000 e=e+1000 -p
       d.mon wx0

   OVERLAP: features partially or completely overlap (using GRASS)
       Select grid boxes (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=boxgrid fill_color=85:130:176
       v.select ainput=boxgrid binput=zipcodes_wake output=v_select_OVERLAP operator=overlap
       d.vect map=v_select_OVERLAP
       d.vect map=zipcodes_wake type=boundary color=50:50:50
       v.select with OVERLAP operator: selected grid boxes shown in grey

   OVERLAPS features spatially overlap (using GEOS)
       Select grid boxes (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=boxgrid fill_color=85:130:176
       v.select ainput=boxgrid binput=zipcodes_wake output=v_select_OVERLAPS operator=overlaps
       d.vect map=v_select_OVERLAPS
       d.vect map=zipcodes_wake type=boundary color=50:50:50
       v.select with OVERLAPS operator: selected grid boxes shown in grey

   DISJOINT: features do not spatially intersect (using GEOS)
       Select grid boxes (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=boxgrid fill_color=85:130:176
       v.select ainput=boxgrid binput=zipcodes_wake output=v_select_DISJOINT operator=disjoint
       d.vect map=v_select_DISJOINT
       d.vect map=zipcodes_wake type=boundary color=50:50:50
       v.select with DISJOINT operator: selected grid boxes shown in grey

   EQUALS: features are spatially equals (using GEOS)
       Select zipcode polygon (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       v.extract input=zipcodes_wake where=ZIPCODE_ID=35 output=zipcodeID35
       v.select ainput=zipcodes_wake binput=zipcodeID35 output=v_select_EQUALS operator=equals
       d.vect map=v_select_EQUALS
       d.vect map=zipcodes_wake type=boundary color=50:50:50
       v.select with EQUALS operator: selected grid boxes shown in grey

   INTERSECTS: features spatially intersect (using GEOS)
       Select zipcode polygons (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=boxgrid fill_color=85:130:176
       v.select ainput=zipcodes_wake binput=boxgrid output=v_select_INTERSECTS operator=intersects
       d.vect map=v_select_INTERSECTS
       d.vect map=boxgrid type=boundary color=50:50:50
       v.select with INTERSECTS operator: selected grid boxes shown in grey

   TOUCHES: features spatially touches (using GEOS)
       Select polygons (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=zipcodeID35 fill_color=85:130:176
       v.select ainput=zipcodes_wake binput=zipcodeID35 output=v_select_TOUCHES operator=touches
       d.vect map=v_select_TOUCHES
       d.vect map=zipcodes_wake type=boundary color=50:50:50
       v.select with TOUCHES operator: selected polygons shown in grey (blue: input polygon)

   CROSSES: features spatially crosses (using GEOS)
       Select zipcode polygons by lines (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=busroute1 color=200:27:27 width=3
       v.select ainput=zipcodes_wake binput=busroute1 output=v_select_CROSSES operator=crosses
       d.vect map=v_select_CROSSES
       d.vect map=zipcodes_wake type=boundary color=50:50:50
       d.vect map=busroute1 color=200:27:27 width=3
       v.select with CROSSES operator: selected polygons shown in grey (red: input lines)

   WITHIN feature A is completely inside feature B (using GEOS)
       Select zipcode polygons (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=boundary_county fill_color=85:130:176
       v.select ainput=zipcodes_wake binput=boundary_county output=v_select_WITHIN operator=within
       d.vect map=v_select_WITHIN
       v.select with WITHIN operator: selected polygons shown in grey (blue: input polygons)

   CONTAINS feature B is completely inside feature A (using GEOS)
       Select zipcode polygon (North Carolina sample dataset):

   CONTAINS with polygons
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=zipcodeID35 fill_color=85:130:176
       v.select ainput=zipcodes_wake binput=zipcodeID35 \
                output=v_select_CONTAINS_pol operator=contains
       d.vect map=v_select_CONTAINS
       v.select  with CONTAINS operator: selected polygon shown in grey (blue: input polygon, not
       visible)

   CONTAINS with points
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=hospitals fill_color=195:31:31 icon=basic/cross3 size=10
       v.select ainput=zipcodes_wake binput=hospitals \
                output=v_select_CONTAINS_pnts operator=contains
       d.vect map=v_select_CONTAINS_pnts
       d.vect map=hospitals fill_color=195:31:31 icon=basic/cross3 size=10
       v.select with CONTAINS operator: selected polygons shown in grey (red: input points)

   RELATE feature A is spatially related to feature B (using GEOS)
       This  operator  additionally  requires  the  relate  parameter  (in   other   GIS   called
       ’ST_Relate’).     This    operator   allows   calculating   the   Dimensionally   Extended
       nine-Intersection Model (DE-9IM).  In the  following  one  example:  Select  polygon  with
       ’TOUCHES’ operator (North Carolina sample dataset):
       d.vect map=zipcodes_wake fill_color=0:128:0
       d.vect map=zipcodeID35 fill_color=85:130:176
       v.select ainput=zipcodeID35 binput=zipcodes_wake \
                output=v_select_TOUCHES_relate operator=relate relate=’T********’
       d.vect map=v_select_TOUCHES
       The  result of relate=’T********’ is the same as seen above in the example ’TOUCHES’.  See
       the DE-9IM page for related operators and their definition.

   Extraction of points falling into a polygon
       Extract fire stations (points) falling into urban area (polygon) - North Carolina data set
       (point in polygon test):
       v.select ainput=firestations binput=urbanarea output=urban_firestations \
                operator=overlap

   Extraction of lines overlapping with a polygon
       Extract  railroad lines from zip code map overlapping with the urban area (line in polygon
       test):
       v.select ainput=railroads binput=urbanarea \
                output=railroads_in_urbanarea operator=overlap

   Extraction of areas overlapping with a line
       Extract those areas from zip code map which overlap with railroads (polygon on line test):
       # first add a tiny buffer around railroad lines:
       v.buffer input=railroads output=railroads_buf20m \
         distance=20
       v.select ainput=zipcodes_wake binput=railroads_buf20m \
         output=zipcodes_wake_railroads operator=overlap

SEE ALSO

        v.category, v.clip, v.overlay, v.extract

       GRASS SQL interface
       GEOS - Geometry Engine, Open Source

AUTHORS

       Radim Blazek
       GEOS support by Martin Landa, Czech Technical University in Prague, Czech Republic
       ZIP code examples by Carol X. Garzon-Lopez, Trento, Italy

       Last changed: $Date: 2018-03-19 21:41:47 +0100 (Mon, 19 Mar 2018) $

SOURCE CODE

       Available at: v.select source code (history)

       Main index | Vector index | Topics index | Keywords index | Graphical index | Full index

       © 2003-2019 GRASS Development Team, GRASS GIS 7.6.1 Reference Manual